The sites layout is presented in the figure below. The sites related to the CoSMOS and Continental Biosphere programmes are located in the vicinity of Toulouse city, in the western eastern part of the domain. The CarboEurope sites are located in the Landes forest area, and in the “intermediate” region, close to the transition between the forested and cultivated areas. This spreading allows us to document the principal land covers:

• the surface energy budget is measured above a mature pine forest, a recently sown forest, a vineyards, maize fields, a wheat field, a rape field, a bean field and grasslands.
• meteorological parameters and temperature and moisture below the surface are measured on most of the above-mentioned sites, plus on a deciduous forest (Agre forest, North of Toulouse city) and a fallow site. Some extra data are collected on operational platforms (close to the sea and the large ponds in the Landes area).

Note that some of these stations are involved in long-term (i.e. > one year) measurement programs.

The CO2 concentration is accurately measured on a 50m tower located 2 km from the shoreline, in order to monitor the upwind conditions for the westerlies which are the most frequent winds in this period of the year. At the same place, the CO2 column is measured with a Fourier transform, infra-red radiometer. In the central part (close to Marmande), the CO2 profile is measured up to 20m.

Wind profiling systems are located in the western half of the domain: UHF radars, measuring between ~200m and ~3000m altitude are located in Cazaux and la Cape Sud, which are at about 10 and 40 kilometers from the shoreline, respectively. This would allow to control the development and penetration of the sea breeze during the course of the day for weak synoptic wind conditions. At La Cape Sud, a Sodar will complement (with overlapping) the UHF wind profile in the lowest layers (50-500m).

A RASS-Sodar, located in the central part of the domain (Marmande), measures the temperature and wind profiles up to an altitude of about 1km.

The map below indicates where the sites are located, their name and abbreviation, the land-use and the main groups operating the instruments. The following table summarizes the measured parameters by the surface platforms.